This invention relates to welding training. More specifically, it relates to a system and method for enabling a welder to calibrate themselves to a target welding speed.
There are many critical elements to creating a high quality weld. Some of these are equipment related, such as having the correct voltage and current, the correct wire or electrode, the correct wire feed speed (in a gas metal arc weld), and correct shielding gas (when used). Other factors are driven by the operator themselves, including welding speed, stickout or contact to work distance, straightness, and orientation of the gun during the weld. Advancements in equipment continue to address equipment-related errors, technology has not been as successfully applied to operator error factors.
While several training aids have been introduced into the market in recent years to help students learn proper welding techniques, the impetus for such products has been around for decades. Indeed, the patent issued to Moberg in 1943 as U.S. Pat. No. 2,333,192 entitled Welder's Training Device describes a simulated stick welding gun, with a retracting welding rod and a visual signal to indicate to the user when they fail to maintain correct arc length on a SMAW system.
Training aids have evolved in the 70 years since then, and there are both simulators such as Lincoln Electric's VRTEX 360 and live action welding trainers such as RealWeld System's trainer which track and report on physical movements during a simulated or real weld, respectively. However, these systems are both complicated and expensive, and are not feasible to implement in every welding booth in a classroom.
Welding speed, or arc speed, in particular, has a large impact on the quality of a weld. If the speed is too great, not enough heat is generated, root penetration decreases, and the bead is too small, making for a weak joint. If the speed is to slow, too much heat is generated, the puddle becomes too large resulting in a large bead, and penetration falls again as heat is absorbed by the large molten puddle and not directed into the base metal. Welding speed also varies considerably based on metal type and thickness. Aluminum requires a much faster welding speed than stainless steel, for example, and a ½ inch plate requires a much slower speed than a ⅛ inch plate to obtain proper penetration and joint strength. Moving too fast results in a weak joint, and moving too slow can also result in burning through the metal altogether.
During the welding process, the welder's attention should be focused on the puddle and maintaining welding tool orientation as well as speed. Trained welders frequently begin a weld session by setting up their equipment, positioning themselves in front of the weldment, and taking several practice runs before they actually strike an arc. These practice runs allow the welder to verify that they can complete the weld in a smooth motion without having to stop to reposition, and allows them to review their tool orientation and practice their speed. There is nothing providing feedback during these practice runs.
There therefore exists a need for a cost effective system that can provide speed feedback prior to a weld to enable the welder to calibrate their muscle memory to the correct speed required for a given welding procedure specification.